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MCP connections, hooks and plugins

Connect Fulcrum Code to MCP tools, manage connection diagnostics, understand lifecycle hooks and plugins, and control extension access.

Connect an MCP server

MCP connects the agent to tools and readable resources supplied by another application. Use /mcp to see the connection commands supported by your installed release, including listing, adding, removing, reloading and diagnosing servers.

  1. Get the server's documented transport, launch command or URL, and authentication requirements.
  2. Add it using the /mcp flow and grant only the access needed for your task.
  3. Complete authentication if the server requires it.
  4. Inspect the server's available tools and run a harmless read to verify the connection.
  5. Remove or disable a connection when it is no longer needed.

Connection settings are stored in ~/.fulcrum/mcp.json. Follow the installed command's help and the server's current instructions rather than copying an old transport example. Server availability, authentication and tool permissions are separate checks.

Diagnose startup

Use the MCP diagnostic command shown by /mcp. If startup stalls, fulcrum --skip-mcp launches without MCP discovery so you can isolate the server problem. A successful connection does not prove a particular tool has permission to write.

Lifecycle hooks

Hooks run shell or Python callbacks around lifecycle events. Supported events include PreToolUse, PostToolUse, UserPromptSubmit, SessionStart, SessionEnd, FileChanged, ModelUsage and SubagentStart. Hook configuration lives in ~/.fulcrum/hooks.json. Hooks execute code; review the command and how it handles input before enabling it.

Plugins and custom commands

User plugins are Python files under ~/.fulcrum/plugins/. They can add tools or slash commands. /plugins reports discovered plugins and loading errors. Treat plugins as executable software, and check compatibility after upgrading Fulcrum Code.

Import existing customisations

/import-claude provides migration for supported skills, agents, plugins, memory and project instructions from Claude Code. Inspect what is copied and resolve conflicting instructions before using it. Imported customisations do not transfer account access or prove that every third-party integration is compatible.

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